One of the most useful measures in prostate cancer diagnosis is an annual prostate specific antigen (PSA) test. There is good evidence to suggest that if the PSA value does not rise beyond a certain threshold over time, the presence of prostate cancer is highly unlikely.
In addition to this, a clinical examination of the prostate should be performed by insertion of a gloved finger into the rectum. This is called a digital rectal examination (DRE) and is important as it enables the doctor to gauge the size, shape and consistency of the prostate. It will also help the doctor to decide whether cancer, infection or an enlarged prostate is present.
Should the PSA test result or the digital rectal examination cause concern, further tests are undertaken including an ultrasound of the prostate which allows visualization of the prostate gland. At the same time a biopsy can be acquired if necessary. The biopsy is studied under the microscope for the presence of abnormal tissue or cancer.
Further diagnostic information can be gained from imaging techniques such as MRI.